Semiconductor packages and methods of packaging semiconductor devices

ABSTRACT

Package substrate, semiconductor packages and methods for forming a semiconductor package are presented. The package substrate includes a base substrate having first and second major surfaces and a plurality of via contacts extending through the first to the second major surfaces of the base substrate. A first conductive layer having a plurality of openings is disposed over the first surface of the base substrate and via contacts. The openings are configured to match conductive trace layout of the package substrate. Conductive traces are disposed over the first conductive layer. The conductive traces are directly coupled to the via contacts through some of the openings of the first conductive layer.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional application of co-pending U.S. patentapplication Ser. No. 13/831,964 filed Mar. 15, 2013, the content ofwhich is hereby incorporated by reference in its entirety for allpurposes.

BACKGROUND

Leadframe-based packages, such as high density leadframe array (HLA)packages, are popular packaging solutions for high I/O devices in theindustry. However, existing leadframe-based packages suffer from severaldisadvantages. For example, leadframe-based packages have limitedcapability in terms of trace routing density and the package levelreliability is limited. There is also a need to increase the efficiencyand reliability of the HLA packages for high frequency applications.

From the foregoing discussion, there is a desire to provide an improvedpackage having very thin package profile, higher I/O counts, fine pitchtrace routing which leads to improved signal routing density and withenhanced electrical performance. It is also desirable to providesimplified methods to form an improved package with relatively low cost.

SUMMARY

Embodiments relate generally to semiconductor packages. In oneembodiment, a package substrate is disclosed. The package substrateincludes a base substrate having first and second major surfaces and aplurality of via contacts extending through the first to the secondmajor surfaces of the base substrate. A first conductive layer having aplurality of openings is disposed over the first surface of the basesubstrate and via contacts. The openings are configured to matchconductive trace layout of the package substrate. Conductive traces aredisposed over the first conductive layer. The conductive traces aredirectly coupled to the via contacts through some of the openings of thefirst conductive layer.

In another embodiment, a semiconductor package is presented. Thesemiconductor package includes a package substrate having first andsecond major surfaces. The package substrate includes a base substrateand a plurality of via contacts extending through the first to thesecond major surface of the package substrate. A first conductive layerhaving first and second type openings is disposed over the first surfaceof the package substrate. The openings are configured to matchconductive trace layout of the package substrate. Conductive traces aredisposed over the first conductive layer. The conductive traces aredirectly coupled to the via contacts through the first type openings ofthe first conductive layer. A die having conductive contacts on itsfirst or second surfaces is disposed over a die region of the packagesubstrate. The conductive contacts of the die are electrically coupledto the conductive traces. A cap disposed over the package substrate toencapsulate the die.

In yet another embodiment, a method for forming a semiconductor packageis presented. The method includes providing a conductive carrier havingfirst and second surfaces. A first conductive layer having first andsecond type openings is formed over the first surface of the conductivecarrier. Conductive traces are formed over the first conductive layer. Adie is mounted on the first surface of the conductive carrier. The dieis coupled to the conductive traces. The die is encapsulated with a cap.The second surface of the conductive carrier is patterned to form viacontacts of a package substrate. The conductive traces are directlycoupled to the via contacts through the first type openings of the firstconductive layer. An insulating layer filling spaces between the viacontacts is formed to form a base substrate of the package substrate.

These embodiments, along with other advantages and features hereindisclosed, will become apparent through reference to the followingdescription and the accompanying drawings. Furthermore, it is to beunderstood that the features of the various embodiments described hereinare not mutually exclusive and can exist in various combinations andpermutations.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, like reference characters generally refer to the sameparts throughout the different views. Also, the drawings are notnecessarily to scale, emphasis instead generally being placed uponillustrating the principles of the invention. In the followingdescription, various embodiments of the present invention are describedwith reference to the following drawings, in which:

FIGS. 1-6 show various embodiments of a semiconductor package; and

FIGS. 7a-l , FIGS. 8a-j , FIGS. 9a-f , FIGS. 10a-f , FIGS. 11a-f , FIGS.12a-e and FIGS. 13a-d show various embodiments of a method for forming asemiconductor package.

DESCRIPTION

Embodiments relate to semiconductor packages and methods for forming asemiconductor package. The packages are used to package one or moresemiconductor dies or chips. For the case of more than one die, the diesmay be arranged in a planar arrangement, vertical arrangement, or acombination thereof. The dies, for example, may include memory devices,logic devices such as mixed signal logic devices, communication devices,RF devices, optoelectronic devices, digital signal processors (DSPs),microcontrollers, system-on-chips (SOCs), micro-electro-mechanicalsystems (MEMS) as well as other types of devices or a combinationthereof. Such packages may be incorporated into electronic products orequipment, such as phones, computers as well as mobile and mobile smartproducts. Incorporating the packages into other types of products mayalso be useful.

FIGS. 1-6 show simplified cross-sectional views of different embodimentsof a semiconductor package. The semiconductor package 100, as shown inFIG. 1, includes a package substrate 101. The package substrate includesfirst and second major surfaces 103 a-b. The first major surface 103 a,for example, may be referred to as the top surface and the second majorsurface 103 b, for example, may be referred to as the bottom surface.Other designations for the surfaces may also be useful. In oneembodiment, the first major surface of the package substrate includesfirst and second regions. The first region 105 a, for example, is a dieor chip region on which a die 110 is mounted and the second region 105b, for example, is a non-die region. In one embodiment, the non-dieregion surrounds the die region. The die region, for example, may bedisposed in a central portion of which the die is mounted and a non-dieregion which is outside of the die region. The die region, for example,may be concentrically disposed within the periphery of the packagesubstrate. Other configurations of die and non-die regions may also beuseful.

In one embodiment, the package substrate includes a base substrate 106and a plurality of via contacts 107 extending from the first to thesecond major surface of the package substrate. In one embodiment, thebase substrate includes a dielectric material, such as solder mask. Thebase substrate may be formed of other suitable types of substratematerials. The base substrate, for example, may be may include anysuitable thickness, depending on manufacturing capabilities. The basesubstrate includes first and second major surfaces 106 a-b, defining thefirst and second major surfaces of the package substrate.

The via contacts 107, in one embodiment, are formed of a singleconductive material. The via contacts, for example, may be formed of amonolithic conductive material. For example, the via contacts may beformed of Cu, Cu alloy, Fe or Ni—Fe alloy. Other suitable types ofconductive materials may also be useful. The via contacts may havetapered or straight profiles. The via contacts, for example, are heldtogether and surrounded by the base substrate. The via contacts, asshown, are isolated from each other by the base substrate.

The via contacts include first and second surfaces 107 a-b. The secondsurface 107 b of the via contacts, in one embodiment, is substantiallycoplanar with the second surface 106 b of the base substrate. In anotherembodiment, the second surface of the via contacts is non-coplanar withthe second surface of the base substrate. For example, the secondsurface of the via contacts may be above or below the second surface ofthe base substrate. The second surface of the via contacts, as shown, isdisposed below or recessed with respect to the second surface of thebase substrate.

The package substrate, in one embodiment, further includes a firstconductive layer 143 having a plurality of openings 149 being disposedover the first surface 103 a of the package substrate. The firstconductive layer, for example, is a patterned or predefined conductivelayer having a plurality of openings which are configured to match theconductive trace layout of the package substrate. The plurality ofopenings is defined based on via contact regions and non-via contactregions of the package substrate. Via contact regions of the packagesubstrate, for example, may be referred to areas where via contacts areformed while non-via contact regions may be referred to areas where novia contacts are formed. In one embodiment, first type openings 149 a ofthe first conducive layer are formed in via contact regions and definelocations under which via contacts are formed. Second type openings 149b of the first conductive layer, in one embodiment, are disposed innon-via contact regions and provides isolation pathway betweenconductive traces.

In one embodiment, the first conductive layer includes a differentmaterial than the via contacts. Any other suitable types of materialsmay be used for the first conductive layer so long as it provides etchselectivity between the first conductive layer and the via contacts orconductive traces which will be described later. For example, the firstconductive layer includes nickel. Other suitable types of conductivematerials, including suitable types of plating material, may also beuseful. The first conductive layer may include any suitable thicknessesand conductive materials, depending on the desired electrical propertiesto suit the required applications.

In one embodiment, conductive traces 130 are disposed on the firstsurface 143 a of the first conductive layer as shown in FIG. 1. Asshown, the conductive traces include a first portion 130 ₁ over thefirst surface 143 a of the first conductive layer 143 while a secondportion 130 ₂ of the conductive traces occupies the first type openings149 a in the first conductive layer. The conductive traces 130, asshown, are directly and fully coupled to the via contacts 107 throughthe first type openings in the first conductive layer, forminginterconnect structures of the package substrate. The first typeopenings 149 a in the first conductive layer 143 provide a conductivepathway between the conductive traces and via contacts.

The conductive traces, in one embodiment, are formed of the sameconductive material as the via contacts, such as copper. In anotherembodiment, the conductive traces may be formed of a different materialthan the via contacts. Other suitable types of conductive material,including suitable types of plating material, may also be useful. Thethickness of the conductive traces, for example, may be as low as about10 μm.

The package substrate further includes contact/bond pads 132 which aredisposed over contact/bond pad regions of the conductive traces. Thecontact pads, in one embodiment, include a single metal layer, such asCu, Al, Ag, or Au. In another embodiment, the contact pads may include amulti-layered stack. The multi-layered stack may include Ni/Pd/Au toform, for example, a wire bondable surface; or Cu, Cu alloy or Cu/Sn toform, for example, a solder wettable surface for flip chip application.Other suitable types of conductive materials may also be useful. Thecontact pads, for example, include the same material as the via contactsand conductive traces. For example, the contact pads include copper. Thecontact pads, for example, may include any suitable thicknesses.

The package substrate may optionally include an insulating layer 140,covering and filling the spaces 139 between the conductive traces in thedie region 105 a of the package substrate as shown in FIG. 1. Theinsulating layer, for example, isolates the conductive traces in the dieregion. Moreover, the insulating layer may also electrically isolate theconductive traces from a second surface of the die. In one embodiment,the insulating layer includes a dielectric material. The dielectricmaterial, for example, includes solder mask, organic dielectric materialsuch as polyimide, benzocyclobutene, etc., or inorganic dielectricmaterial such as SiO₂, AlN, Al₂O₃, etc. Other suitable types ofdielectric materials may also be useful.

In one embodiment, an adhesive layer 150 may be used to mount a die 110to the package substrate. The die 110 can be a semiconductor die orchip. The die includes first and second major surfaces. The firstsurface 110 a, for example, is an inactive surface of the die and thesecond surface 110 b is an active surface of the die. Other designationsfor the surfaces of the die may also be useful. The active surface, forexample, includes openings (not shown) in a final passivation layer toexpose conductive die pads/contacts (not shown). The surfaces of the diepads, for example, are substantially coplanar with the second surface ofthe die. Providing surfaces of the conductive pads which are notcoplanar with the second major surface of the die may also be useful.The die pads provide connections to the circuitry of the die. The diepads, for example, are formed of a conductive material, such as copper,aluminum, gold, nickel or alloys thereof. Other types of conductivematerial may also be used for the die pads. The pattern of the die padsmay be one or more rows disposed at the periphery of the active surface.Other pad patterns may also be useful.

The inactive surface of the die is mounted to the die region of thepackage substrate with the use of the adhesive layer. The adhesive layer150, for example, may include an adhesive paste or die attach film, suchas tape. Other types of adhesive, such as epoxy, may also be useful. Inone embodiment, wire bonds 112 are provided to couple the die pads onthe die to the conductive traces 130. The wire bonds create electricalconnection between the conductive traces of the package substrate anddie pads on the die.

In one embodiment, a cap 190 is disposed on top of the packagesubstrate, encapsulating the die and the wire bonds. The cap serves toprotect the die from the environment. For example, the cap may protectthe die from moisture. The cap, for example, is formed of anencapsulation material. The encapsulation material, for example, mayinclude molding epoxy resin material. Other suitable types ofencapsulation materials may also be useful.

The cap includes first and second major surfaces 190 a-b. The firstsurface 190 a, for example, may be the top surface and the secondsurface 190 b may be the bottom surface. Other designations for thesurfaces of the cap may also be useful. In one embodiment, the capsurrounds and covers the die and the wire bonds. The second surface 190b of the cap, in one embodiment, includes a non-planar surface. Forexample, portions of the second surface of the cap include protrudedportions 190 p which occupy the second type openings 149 b of the firstconductive layer and spaces 139 between the conductive traces. Theprotruded portions of the cap, in one embodiment, isolate the conductivetraces. The surface of the protruded portions of the cap, in oneembodiment, contact portions of the first surface 106 a of the basesubstrate. The protruded portions of the cap isolate the conductivetraces in the non-die region of the package substrate while thedielectric material of the optional insulating layer isolates theconductive traces in the die region of the package substrate.

Package contacts 160 are disposed on the second surface 107 b of the viacontacts. The package contacts, for example, are spherical shapedstructures or balls. The package contacts protrude from the secondsurface 103 b of the package substrate. Providing package contacts whichdo not protrude from the bottom surface of the package substrate, suchas solder lands, may also be useful. The package contact is formed of aconductive material. The package contacts, for example, can be formedfrom solder. Various types of solder can be used to form the packagecontacts. For example, the solder can be a lead-based or non lead-basedsolder. Other types of conductive materials may also be used to form thepackage contacts.

The package contacts provide external access to the die via theconductive traces, via contacts and die pads. The package may beelectrically coupled to an external device (not shown), such as acircuit board, by the package contacts.

The package substrate, as described for example in FIG. 1, includes viacontacts in the die and non-die regions. As such, the package substrateserves as fan-in and fan-out redistribution structure for the diecontacts, enabling redistributed external package connections. Inanother embodiment, the package substrate may be modified. For example,via contacts may be provided only in the non-die regions, as shown inFIG. 2. As such, the package substrate serves as fan-out redistributionstructure for the die contacts.

The semiconductor packages 100-200, as shown in FIGS. 1 and 2, include awire bonded die. In another embodiment, the semiconductor packages mayinclude a flip chip type of die (not shown). It is understood thatmodifications may be made to form contact pads which matches the diecontacts of the flip chip for flip chip applications. It is alsounderstood that for flip chip application, first surface of the cap maybe covering the inactive surface of the flip chip or substantiallycoplanar with the inactive surface of the flip chip. As such, detailsfor flip chip application may not be described or described in detail.

As described in the embodiments of FIGS. 1-2, the package substrateincludes a patterned or predefined first conductive layer having aplurality of openings which are configured to match the conductive tracelayout of the package substrate. The first type openings in the firstconductive layer provide a conductive pathway between the conductivetraces and via contacts. This allows direct coupling of the conductivetraces to the via contacts which form the interconnect structures of thepackage substrate. Such configuration also ensures full connectionwithin a signal interconnect structure, leading to enhanced electricalconductivity. Moreover, in embodiments where the conductive traces andvia contacts include the same material, electrical resistance of theinterconnect structure is reduced. This further improves electricalperformance of the semiconductor package which allows packages to beemployed more efficiently in, for example, high frequency applications.

Furthermore, as described in embodiments of FIGS. 1-2, the packagesubstrate includes a plurality of via contacts held together andsurrounded by the base substrate. As such, the via contacts will not bedetached easily. This allows for improved robustness and reliability,relative to other types of packages. Furthermore, the second surface ofthe via contacts, in one embodiment, is disposed below or recessed withrespect to the second surface of the base substrate. Such configurationis advantageous as it provides recesses or pockets for better receivingof package contacts. Additionally, the package substrate, as describedfor example in FIG. 1, includes via contacts in the die and non-dieregions. As such, the package substrate serves as fan-in and fan-outredistribution structure for the die contacts, enabling redistributedexternal package connections. This leads to an increased number of I/Oto be available in a given package area. The package substrate asdescribed involves relatively low manufacturing cost and may potentiallybe used to replace BGA substrate. In addition, the package substrateincludes package contacts and via contacts. The combination of thepackage contacts and the via contacts as described may improve thepackage board level reliability performance due to improved stand-offheight. The semiconductor package may also be modified for flip chipapplications. In embodiments where the first surface of the cap issubstantially coplanar with the inactive surface of the flip chip, theinactive surface of the flip chip is exposed for dissipating heat. Suchpackage has improved thermal performance. Additionally, suchconfiguration also allows for inclusion of additional heat sink or heatspreader to further enhance heat dissipation.

FIGS. 3-6 show various other embodiments of a semiconductor package. Thesemiconductor package 300 of FIG. 3 is similar to that described inFIG. 1. For example, the package substrate 101 includes a plurality ofvia contacts 107 held together and surrounded by the base substrate 106.A first conductive layer 143 having predefined openings 149 a-b isdisposed on the first surface of the package substrate and packagecontacts 160 are disposed on the second surface 107 b of the viacontacts, similar to that described in FIG. 1. As such, common elementsmay not be described or described in detail.

The base substrate 106, in one embodiment, differs from the basesubstrate of FIG. 1 in that the first surface 106 a of the basesubstrate includes a non-planar surface. As shown in FIG. 3, portions ofthe first surface 106 a of the base substrate is substantially coplanarwith the first surface 107 a of the via contacts while portions of thefirst surface of the base substrate include protruded portions 106 pwhich partially occupy the second type openings 149 b of the firstconductive layer.

The package substrate, as shown in FIG. 3, includes conductive traces330. In one embodiment, the first portion 330 ₁ of the conductive tracesis disposed over the first surface 143 a of the first conductive layerwhile the second portion 330 ₂ of the conductive traces line the sidesand bottom of the first type openings 149 a of the first conductivelayer, forming recessed portion of the conductive traces. The conductivetraces 330, in one embodiment, are directly coupled to the via contacts107 through the recessed portions 330 ₂ of the conductive traces in thefirst type openings 149 a of the first conductive layer, forminginterconnect structures of the package substrate. The first typeopenings 149 a provide a conductive pathway between the conductivetraces and via contacts.

The package substrate, in one embodiment, includes a dielectric layer340 disposed over the conductive traces in the die and non-die regionsof the package substrate. In one embodiment, the dielectric layerincludes a solder mask, organic dielectric material such as polyimide,benzocyclobutene, etc., or inorganic dielectric material such as SiO₂,AlN, Al₂O₃, etc. Other suitable types of dielectric material may also beuseful. The dielectric layer covers sides/edges and first surface 330 aof the conductive traces and fill the spaces 139 between the conductivetraces. In one embodiment, the dielectric layer isolates the bond pads132 and the conductive traces 330 in the die and non-die regions of thepackage substrate. The dielectric layer, in one embodiment, includes aplanar first surface 340 a as shown in FIG. 3. The planar first surfaceof the dielectric layer, in one embodiment, is substantially coplanarwith the first surface 132 a of the bond pads. Providing a planar firstsurface of the dielectric layer which is non-coplanar with the firstsurface of the bond pads may also be useful.

A die 110 is mounted to the package substrate by an adhesive layer 150,similar to that described in FIG. 1. In one embodiment, the adhesive isdisposed in the die region of the package substrate over the planarfirst surface of the dielectric layer. Wire bonds 112, for example, areprovided to couple the die pads on the die to the bond pads. The bondpads are coupled to the conductive traces at the non-die region of thepackage substrate which are coupled to the via contacts as shown in FIG.3. As such, features of the die will not be described or described indetail.

In one embodiment, a cap 390 having first and second surfaces 390 a-b isformed over the dielectric layer, encapsulating the die and the wirebonds. In one embodiment, the cap surrounds and covers the die and thewire bonds. The second surface of the cap 390 b, in one embodiment,includes a planar surface and contacts the first surface 340 a of thedielectric layer. As shown in FIG. 3, the second surface of the cap isseparated from the base substrate of the package substrate by thedielectric layer.

FIG. 4 shows another embodiment of a semiconductor package 400. Thesemiconductor package of FIG. 4 is similar to that described in FIGS. 1and 3. For example, the package substrate includes a plurality of viacontacts 107 held together and surrounded by the base substrate 106. Thebase substrate includes a non-planar first surface, the same as thatdescribed in FIG. 3. A first conductive layer 143 having predefinedopenings 149 a-b is disposed on the first surface of the packagesubstrate and package contacts 160 are disposed on the second surface107 b of the via contacts, similar to that described in FIG. 1. Thefirst portion 330 ₁ of the conductive traces is disposed over the firstsurface 330 a of the first conductive layer while the second portion 330₂ of the conductive traces line the sides and bottom of the first typeopenings of the first conductive layer, forming recessed portion of theconductive traces. As such, common elements may not be described ordescribed in detail.

The package substrate, in one embodiment, includes a dielectric layer440 disposed over the conductive traces in the die and non-die regionsof the package substrate. The dielectric layer 440, in one embodiment,differs from the dielectric layer 340 of the package substrate of FIG. 3in that the dielectric layer 440 includes first and second type openings449 a-b. The openings of the dielectric layer may be defined based onvia contact regions and non-via contact regions of the packagesubstrate. In one embodiment, first type openings 449 a of thedielectric layer in the via contact regions expose the recessed portions330 ₂ of the conductive traces which are coupled to the via contactswhile the second type openings 449 b in the non-via contact regionsexpose surfaces of the protruded portions 106 p of the base substrate.

A die 110 is mounted to the package substrate by an adhesive layer 150which is disposed in the die region of the package substrate, similar tothat described in FIG. 3. As such, features of the die and theelectrical connection of the die will not be described or described indetail.

In one embodiment, a cap 490 having first and second surfaces 490 a-b isformed over the dielectric layer 440, encapsulating the die 110 and thewire bonds 112. In one embodiment, the cap surrounds and covers the dieand the wire bonds. The second surface of the cap 490 b, in oneembodiment, includes a non-planar surface. As shown in FIG. 4, portionsof the second surface 490 b of the cap include protruded portions 490 pwhich occupy the openings 449 a-b of the dielectric layer. The protrudedportions of the cap, in one embodiment, isolate the conductive traces.The surface of the protruded portions of the cap, in one embodiment,contact the protruded portions 160 p of the base substrate in thenon-via contact regions while contact the recessed portions 330 ₂ of theconductive traces in the via contact regions. The cap material and theprotruded portions of the base substrate 106 p isolate the conductivetraces 330 in the non-die region 105 b of the package substrate whilethe dielectric material of the dielectric layer 440 and the protrudedportions of the base substrate 106 p isolate the conductive traces inthe die region 105 a of the package substrate.

FIG. 5 shows another embodiment of a semiconductor package 500. Thesemiconductor package of FIG. 5 is similar to that described in FIGS. 1,3 and 4. For example, the package substrate includes a plurality of viacontacts 107 held together and surrounded by the base substrate 106. Thebase substrate includes a non-planar first surface, the same as thatdescribed in FIGS. 3 and 4. A first conductive layer 143 havingpredefined openings 149 a-b is disposed on the first surface of thepackage substrate and package contacts 160 are disposed on the secondsurface 107 b of the via contacts, similar to that described in FIG. 1.The first portion 330 ₁ of the conductive traces is disposed over thefirst surface 143 a of the first conductive layer while the secondportion 330 ₂ of the conductive traces line the sides and bottom of thefirst type openings 149 a of the first conductive layer, formingrecessed portion of the conductive traces. As such, common elements maynot be described or described in detail.

The package substrate, in one embodiment, includes a dielectric layer540 disposed over the conductive traces 330. The dielectric layer 540,in one embodiment, differs from the dielectric layer 440 of packagesubstrate of FIG. 4 in that the dielectric layer 540 is disposed in thedie region 105 a of the package substrate. The dielectric layer 540 inthe die region, for example, provides a planar die attach surface toensure co-planarity across the die surface after the die attachmentprocess.

A die 110 is mounted to the package substrate by an adhesive layer 150which is disposed in the die region of the package substrate, similar tothat described in FIGS. 3 and 4. As such, features of the die and theelectrical connection of the die will not be described or described indetail.

In one embodiment, a cap 590 having first and second surfaces 590 a-b isformed over the package substrate, encapsulating the die 110 and thewire bonds 112. In one embodiment, the cap surrounds and covers the dieand the wire bonds. The second surface of the cap 590 b, in oneembodiment, includes a non-planar surface. As shown in FIG. 5, thesecond surface of the cap includes protruded portions which occupy theopenings separating the conductive traces. The surface of the protrudedportions 590 p of the cap, in one embodiment, contact the protrudedportions 106 p of the base substrate in the non-via contact regionsincluding the peripheries 103 c-d of the package substrate while contactthe recessed portions 330 ₂ of the conductive traces in the via contactregions. The cap material and the protruded portions of the basesubstrate 106 p isolate the conductive traces 330 in the non-die region105 b of the package substrate while the dielectric material of thedielectric layer 540 and the protruded portions of the base substrate106 p isolate the conductive traces 330 in the die region of the packagesubstrate.

FIG. 6 shows another embodiment of a semiconductor package 600. Thesemiconductor package of FIG. 6 is similar to that described in FIGS. 1,3, 4 and 5. For example, the package substrate includes a plurality ofvia contacts 107 held together and surrounded by the base substrate 106.The base substrate 106 includes a non-planar first surface, the same asthat described in FIGS. 3, 4 and 5. A first conductive layer 143 havingpredefined openings 149 a-b is disposed on the first surface of thepackage substrate and package contacts 160 are disposed on the secondsurface 107 b of the via contacts, similar to that described in FIG. 1.The first portion 330 ₁ of the conductive traces is disposed over thefirst surface 143 a of the first conductive layer while the secondportion 330 ₂ of the conductive traces line the sides and bottom of thefirst type openings of the first conductive layer in the via contactsregions, forming recessed portion of the conductive traces. As such,common elements may not be described or described in detail.

The package substrate, in one embodiment, differs from the packagesubstrate of FIG. 5 in that the no dielectric layer is disposed over theconductive traces.

A die 110 is mounted to the package substrate by an adhesive layer 150which is disposed in the die region of the package substrate, similar tothat described in FIGS. 3 and 4. As such, features of the die and theelectrical connection of the die will not be described or described indetail.

In one embodiment, a cap 690 having first and second surfaces 690 a-b isformed over the conductive traces 330, encapsulating the die 110 and thewire bonds 112. In one embodiment, the cap surrounds and covers the dieand the wire bonds. The second surface of the cap 690 b, in oneembodiment, includes a non-planar surface. As shown in FIG. 6, thesecond surface of the cap includes protruded portions 690 p which occupythe spaces 139 separating the conductive traces. The surface of theprotruded portions 690 p of the cap, in one embodiment, contact theprotruded portions 106 p of the base substrate in the non-via contactregions including the peripheries 103 c-d of the package substrate whilecontact the recessed portions 330 ₂ of the conductive traces in the viacontact regions. The cap material and the protruded portions of the basesubstrate 106 p isolate the conductive traces in the die and non-dieregions 105 a-b of the package substrate.

The semiconductor packages, as shown in FIGS. 3-6, include a wire bondeddie. In another embodiment, the semiconductor packages may include aflip chip type of die (not shown). It is understood that modificationsmay be made to form contact pads which matches the die contacts of theflip chip for flip chip applications. It is also understood that forflip chip application, first surface of the cap may be covering theinactive surface of the flip chip or substantially coplanar with theinactive surface of the flip chip. As such, details for flip chipapplication may not be described or described in detail.

The embodiments described with respect to FIGS. 3-6 include some or alladvantages as described with respect to FIGS. 1-2. As such, theseadvantages will not be described or described in detail. Moreover, asdescribed in the embodiments of FIGS. 3-6, portions of the first surfaceof the base substrate include protruded portions 106 p which partiallyoccupy the second type openings 149 b of the first conductive layer. Assuch, the second type openings 149 b in the first conductive layer inthe non-via contact regions of the package substrate provide moresurface area for the base substrate to effectively hold the viacontacts. As such, the reliability of the semiconductor package isfurther enhanced.

The embodiments, as described in FIGS. 1-6, show a semiconductor packagehaving a wire bonded type of die. It is understood that other suitabletypes of dies, such as flip chip or TSV type of dies, may also beuseful. The semiconductor packages, as illustrated in FIGS. 1-6, includea single die. It is understood that the semiconductor package, may alsoinclude a die stack (not shown). The die stack includes x number ofdies, where x is ≧2. In addition, it is understood that the dies of thedie stack may be the same size or type. Providing a die stack havingchips which are different types and/or sizes is also useful.

FIGS. 7a-l show an embodiment of a method for forming a semiconductorpackage. Referring to FIG. 7a , a base carrier 707 or a leadframe isprovided. The base carrier, in one embodiment, includes a conductivecarrier having first and second major surfaces 707 a-b. The first andsecond major surfaces, for example, include planar surfaces. Providingany one of the major surfaces to be non-planar may also be useful. Theconductive carrier, for example, includes Cu, Cu alloy, Fe or Ni—Fealloy. Other suitable types of conductive materials may also be useful.The thickness of the conductive carrier, for example, is about 100-300μm. Other suitable thicknesses may also be useful. The conductivecarrier, for example, may serve as part of the interconnect structures,such as via contacts, of the package substrate as will be describedlater.

Referring to FIG. 7b , a first conductive layer 143 having a pluralityof first type openings 149 a is formed over the first surface of theconductive carrier 707 a. The first conductive layer 143, for example,is a patterned or predefined conductive layer having a plurality ofopenings which are configured to match the conductive trace layout ofthe package substrate. The plurality of openings is defined based on viacontact regions and non-via contact regions of the package substrate.Via contact regions of the package substrate, for example, may bereferred to areas where via contacts are formed while non-via contactregions may be referred to areas where no via contacts are formed. Inone embodiment, first type openings 149 a of the first conducive layerare formed in via contact regions and define locations under which viacontacts are formed.

In one embodiment, the first conductive layer 143 having predefinedopenings is formed by plating. For example, electrochemical orelectroless plating may be employed to form the first conductive layer.For example, a patterned mask layer (not shown) may be provided over thefirst surface 707 a of the conductive carrier. A plating process isperformed. The first conductive layer may be selectively plated over theexposed portions of the first surface of the conductive carrier notcovered by the patterned mask layer. The conductive carrier thus alsoserves as a base or substrate for the electroplating process for formingthe first conductive layer. Other suitable types of techniques may alsobe employed to form the first conductive layer.

The first conductive layer, in one embodiment, includes a differentmaterial than the material of the conductive carrier. Any other suitabletypes of materials may be used for the first conductive layer so long asit provides etch selectivity between the first conductive layer and thevia contacts or conductive traces which will be described later. Forexample, the first conductive layer includes nickel. Other suitabletypes of conductive materials, including suitable types of platingmaterial, may also be useful. The first conductive layer may include anysuitable thicknesses and conductive materials, depending on the desiredelectrical properties to suit the required applications. The processcontinues to remove the patterned mask layer, thus forming the firstconductive layer having first type openings 149 a as shown in FIG. 7b .As shown, the openings 149 a expose portions of the first surface of theconductive carrier.

The process continues to form conductive traces of the package substrateas shown in FIG. 7c . For example, electrochemical or electrolessplating may be employed to form the conductive traces. In oneembodiment, a patterned mask layer (not shown) may be provided over theconductive carrier. A plating process is performed. In one embodiment, asecond conductive layer, which includes the same material as theconductive carrier 707, such as copper, may be selectively plated overthe exposed portions of the first surface of the first conductive layernot covered by the patterned mask layer to form conductive traces 130.The first conductive layer 143 thus also serves as a base or substratefor the electroplating process for forming the conductive traces. Othersuitable techniques may also be used to form the conductive traces. Thethickness of the plated conductive traces 130, for example, is about50-150 μm. The thickness of the plated conductive traces, for example,may also be as low as about 10 μm. Other suitable thicknesses may alsobe useful. As shown, the plated conductive traces include a firstportion 130 ₁ over the first surface 143 a of the first conductive layerwhile a second portion 130 ₂ of the conductive traces fill the firsttype openings 149 a in the first conductive layer. The process continuesto remove the patterned mask layer, thus forming the conductive traceshaving predefined openings/spaces 139 separating the conductive tracesas shown in FIG. 7 c.

The process continues by removing portions of the first conductive layerto form second type openings 149 b in the first conductive layer. Secondtype openings 149 b of the first conductive layer, in one embodiment,are formed in non-via contact regions. In one embodiment, portions ofthe first conductive layer may be removed by a patterning process.Patterning of the first conductive layer can be achieved by any suitableetching techniques. The patterning of the first conductive layer may beperformed without a need of a patterned mask. In one embodiment,portions of the first conductive layer may be removed using theconductive traces as the etch mask. An etch may be performed using theconductive traces to remove portions of the first conductive layer. Asshown in FIG. 7d , portions of the first conductive layer exposed by thespaces 139 between the conductive traces 130 are removed to create thesecond type openings 149 b in the first conductive layer. As such,portions of the first surface 707 a of the conductive carrier in theopenings are exposed. The etch, for example, may be a wet etch. Othersuitable techniques may also be employed to remove portions of the firstconductive layer. The openings 709, as shown, extend from the firstsurface of the conductive traces to the second surface of the firstconductive layer. The openings, for example, may have tapered orstraight profiles. A partially processed package substrate is thusformed as shown in FIG. 7 d.

The process continues by forming contact/bond pads over, for example,portions of the conductive traces. In one embodiment, a dielectric layer740 having predefined openings 749 is provided over the conductivetraces 130. The dielectric layer, in one embodiment, includes a soldermask. The solder mask, in one embodiment, is predefined with a pluralityof openings which define areas over the conductive traces where bondpads are to be formed while the solder mask covers the non-bond padregions of the conductive traces. For example, the solder mask fill theopenings 709 and covers edges of the conductive traces and the firstconductive layer as well as portions of the first surface 130 a of theconductive traces which are to be kept free of bond pads. The openings709, for example, may be formed by exposure and development techniques.Other suitable techniques may also be used to form the openings 709. Inanother embodiment, the bond pads may be formed over the entireconductive traces.

Referring to FIG. 7f , contact/bond pads 132 are formed in the openings749 of the dielectric layer. In one embodiment, the bond pads are formedby a plating process. A conductive layer, which may include the samematerial as the conductive carrier and traces, such as copper, may beselectively plated over the exposed portions of the first surface 130 aof the conductive traces not covered by the dielectric layer to form thebond pads. As such, the dielectric layer also serves as a plating mask.The first surface 130 a of the conductive traces also serves as a baseor substrate for the electroplating process for forming the bond pads.Other suitable types of conductive material, such as Al, Ag, or Au mayalso be plated. In another embodiment, the contact pads may include amulti-layered stack. The multi-layered stack may include Ni/Pd/Au toform, for example, a wire bondable surface; or Cu, Cu alloy or Cu/Sn toform, for example, a solder wettable surface for flip chip application.Other suitable types of conductive materials may also be useful. Thethickness of the plated bond pads, for example, is about 0.01-1.5 μm.Other suitable thicknesses may also be useful. The bond pads, forexample, may include a first surface 132 a which is substantiallycoplanar with first surface 740 a of the dielectric layer. Providingfirst surface 132 a of the bond pads which is non-coplanar with thefirst surface of the dielectric layer may also be useful.

In one embodiment, the process continues to remove the dielectric layer740, such as the solder mask, as shown in FIG. 7g . The dielectric layer740, for example, may be removed by etching. Other suitable techniquesmay be employed to remove the dielectric layer. As shown, the dielectriclayer is removed, leaving bond pads 132 over the bond pad regions of theconductive traces. In an alternative embodiment, the dielectric layer740 need not be removed and serves as isolation layers between theconductive traces.

An insulating layer 140 may optionally be provided, covering and fillingthe spaces between the conductive traces in a die region 105 a of thepackage substrate after removing the dielectric layer 740 as shown inFIG. 7h . The insulating layer 140 isolates the conductive traces 130 inthe die region. In one embodiment, the insulating layer includes adielectric material, such as solder mask, organic dielectric materialsuch as polyimide, benzocyclobutene, etc., or inorganic dielectricmaterial such as SiO₂, AlN, Al₂O₃, etc. The insulating layer, forexample, may be formed by dispensing, laminating, screen printing,followed by exposure and development techniques. Other types ofdielectric materials and techniques may also be used for forming theinsulating layer.

Referring to FIG. 7h , a die 110 or a semiconductor chip which includescircuit components is attached to the die region 105 a of the packagesubstrate. The circuit components include, for example, transistors,resistors, capacitors and interconnections to form an IC. A finalpassivation layer (not shown) may be formed over the die. The finalpassivation layer includes openings (not shown) to expose diepads/contacts (not shown). The surface of the die which includes theopenings to the die pads may be referred to as the active surface 110 bof the die. In one embodiment, an adhesive layer 150 may be used tomount the die to the die region of the package substrate. For example,the inactive surface 110 a of the die is mounted to the packagesubstrate with the use of the adhesive layer. The adhesive layer, forexample, may include an adhesive paste or die attach film, such as tape.Other types of adhesive, such as epoxy, may also be useful. In oneembodiment, wire bonds 112 are formed to create electrical connectionbetween the bond pads which are coupled to the conductive traces on thepackage substrate and die pads on the die.

A cap 190 is formed on the package substrate. For example, anencapsulation material is dispensed to encapsulate the die 110 and thewire bonds 112. In one embodiment, the encapsulation material includes amold compound, such as molding epoxy resin material. Providing othertypes of encapsulation materials may also be useful. The cap includesfirst and second major surfaces 190 a-b. In one embodiment, theencapsulation material fills the openings 709 between the conductivetraces in the non-die region 105 b and the second surface 109 b of thecap contacts the first surface 707 a of the conductive carrier.

The cap, in one embodiment, is formed by transfer molding techniques.Encapsulation material, such as a mold compound, is dispensed into themold assembly to form the cap. After molding, the molded die isseparated from the mold. Other suitable types of techniques for formingthe cap may also be useful. For example, the cap may also be formed byprinting or compression molding.

In FIG. 7i , the second surface 707 b of the conductive carrier isprocessed. In one embodiment, portions of the conductive carrier 707 areremoved. For example, the second surface of the conductive carrier ispatterned to remove excess material. For example, the conductive carrieris thinned or removed up to a suitable thickness. The thickness of theconductive carrier after the removal process, for example, is about 5-10μm. The conductive carrier may be thinned to a desired via contactthickness. The second major surface of the conductive carrier may beremoved using etch, grinding or polishing technique. The etch, forexample, includes wet etch/chemical etch. Other techniques for thinningthe conductive carrier may also be useful.

The process continues to form via contacts 107 of the package substrateas shown in FIG. 7j . In one embodiment, the via contacts 107 of thepackage substrate are formed by patterning the remaining conductivecarrier. Patterning of the conductive carrier may be performed with thehelp of a patterned masked layer. Patterning of the conductive carriercan be achieved by any suitable etching techniques. For example, apatterned etch mask (not shown), such as photoresist, is provided overthe second surface 717 of the thinned conductive carrier. An etch may beperformed using the etch mask to remove portions of the conductivecarrier unprotected by the etch mask. The etch, for example, may be anisotropic etch, such as a wet etch. Other techniques for patterning theconductive carrier may also be useful. The thickness of the via contactsas formed, for example, is substantially the same as the thickness ofthe thinned conductive carrier. The conductive vias, for example, mayalso include other suitable thicknesses. The via contacts 107 arecoupled to the conductive traces 130. As shown, the first type openings149 a in the first conductive layer allows the via contacts 107 to bedirectly coupled to the conductive traces 130 to form interconnectstructures of the package substrate. The first type openings 149 a ofthe first conductive layer 143 in the via contact regions thus provide aconductive pathway between the conductive traces and via contacts whilethe second type openings 149 b of the first conductive layer in thenon-via contact regions provide isolation pathway between conductivetraces.

After patterning the conductive carrier, the mask is removed. The mask,for example, may be removed by ashing. Other techniques for removing themask may also be useful.

An insulating layer 106, in one embodiment, is provided, filling thespaces 779 between the via contacts as shown in FIG. 7k . The insulatinglayer isolates the via contacts. In one embodiment, the insulating layerincludes a dielectric material such as solder mask. The insulatinglayer, for example, may be formed by any suitable types of dielectricmaterials and techniques. The insulating layer formed in between the viacontacts may be referred to as the base substrate 106 of the packagesubstrate.

The second surface of the via contacts 107 b, in one embodiment, aresubstantially coplanar with the second surface 106 b of the basesubstrate. In another embodiment, the second surface of the via contactsare non-coplanar with the second surface of the base substrate as shownin FIG. 7k . For example, the second surface of the via contacts may beabove or below the second surface of the base substrate.

The process continues by forming package contacts 160 coupled to the viacontacts, as shown in FIG. 7l . For example, the package contacts areformed on the second surface 107 b of the via contacts. The packagecontacts, for example, may include spherical shaped structures or ballsarranged in grid pattern to form a BGA type package. As such, asemiconductor package such as that shown in FIG. 1 is formed. Thepackage contacts are formed of a conductive material. The packagecontacts, for example, can be formed from solder. Various types ofsolder can be used to form the package contacts. For example, the soldercan be a lead-based or non lead-based solder.

In some embodiments, other types of package contacts are coupled to thevia contacts. For example, the package contacts may include contactswhich do not protrude from the bottom surface of the package substrate.Providing package contacts which do not protrude from the bottom surfaceof the package substrate, such as solder lands, may also be useful. Thepackage contacts may be formed of materials other than solder, such asanisotropic conductive film (ACF), or using other techniques.

The process as described with respect to FIGS. 7a-l is suitable for wirebonded type of die or chip packages. The process may also be useful forother types of dies, including flip chip type of dies. It is understoodthat modifications may be made to form conductive pads which matches thepattern of die contacts of a flip chip (not shown). It is alsounderstood that for flip chip application, first surface of the cap maybe covering the inactive surface of the flip chip or substantiallycoplanar with the inactive surface of the flip chip. As such, detailsfor flip chip application may not be described or described in detail.

The processes, as described with respect to FIGS. 7a-l , result inadvantages. As described in FIGS. 7a-l , the package substrate includesa patterned or predefined first conductive layer having a plurality ofopenings which are configured to match the conductive trace layout ofthe package substrate. The first type openings in the first conductivelayer provide a conductive pathway between the conductive traces and viacontacts. This allows direct coupling of the conductive traces to thevia contacts which form the interconnect structures of the packagesubstrate. Such configuration also ensure full connection within asignal interconnect structure, leading to enhanced electricalconductivity. Moreover, in embodiments where the conductive traces andvia contacts include the same material, electrical resistance of theinterconnect structure is reduced. This further improves electricalperformance of the semiconductor package which allows packages to beemployed more efficiently in, for example, high frequency applications.

In addition, the first conductive layer, in one embodiment, is platedonto the conductive carrier for better handling. For example, the firstconductive layer, such as nickel, acts as a barrier or etch stop layerduring the removal of portions of the conductive carrier to form viacontacts. As such, the conductive traces at the non-via contact regionswill not be overetched during the removal of portions of the conductivecarrier.

As described, the conductive traces, in one embodiment, are formed byplating. This allows better control of the thickness of the conductivetraces. For example, conductive traces with finer or thinner profile canbe formed, leading to fine linewidth/space trace routing. Finelinewidth/space trace routing is advantageous as it enables higherrouting density and more complex signal interconnection to be achieved.Moreover, it allows the location of package contacts or via contacts tobe flexibly designed according to various customers' needs.

Furthermore, as described in embodiments of FIGS. 1-2, the packagesubstrate includes a plurality of via contacts held together andsurrounded by the base substrate. As such, the via contacts will not bedetached easily. This allows for improved robustness and reliability,relative to other types of packages. Furthermore, the second surface ofthe via contacts, in one embodiment, is disposed below or recessed withrespect to the second surface of the base substrate. Such configurationis advantageous as it provides recesses or pockets for better receivingof package contacts. The method as described in FIGS. 7a-l enablespackage substrate which includes via contacts in the die and non-dieregions to be formed. As such, the package substrate serves as fan-inand fan-out redistribution structure for the die contacts, enablingredistributed external package connections. This leads to an increasednumber of I/O to be available in a given package area. The method asdescribed involves relatively low manufacturing cost and may potentiallybe used to replace BGA substrate. In addition, the package substrateincludes package contacts and via contacts. The combination of thepackage contacts and the via contacts as described may improve thepackage board level reliability performance due to improved stand-offheight. The process as described in FIGS. 7a-l may also be modified forflip chip applications. In embodiments where the first surface of thecap is substantially coplanar with the inactive surface of the flipchip, the inactive surface of the flip is exposed for dissipating heat.Such package has improved thermal performance. Additionally, suchconfiguration also allows for inclusion of additional heat sink or heatspreader to further enhance heat dissipation.

FIGS. 8a-j show another embodiment of a process for forming asemiconductor package. The process is similar to that described in FIGS.7a-l . As such, common elements may not be described or described indetail.

In one embodiment, a first conductive layer 143, such as a nickel layer,having first and second type openings 149 a-b is formed over the firstsurface 707 a of the conductive carrier. For example, the firstconductive layer 143 having first and second type openings 149 a-b asshown in FIG. 8a is formed by plating or other suitable methods asdescribed in FIG. 7 b.

The process continues to form conductive traces or routings of thepackage substrate as shown in FIG. 8b . For example, electrochemical orelectroless plating may be employed to form the conductive traces. Inone embodiment, a second conductive layer 830, which includes the samematerial as the conductive carrier, such as copper, is blanket platedover the first conductive layer 143, lining the sides/edges and firstsurface 143 a of the first conductive layer as well as bottom of theopenings 149 a to form the conductive trace layer 830. Other suitabletypes of conductive material may also be useful. The thickness of theplated conductive trace layer, for example, is about 50-150 μm. Thethickness of the plated conductive trace layer, for example, may also beas low as about 10 μm. Other suitable thicknesses may also be useful. Asshown, the plated conductive trace layer follows the topography of thefirst conductive layer and lines the bottom of the openings. As a resultof the blanket plating process, the second conductive layer includesfirst portions 830 ₁ which are planar and disposed over the firstsurface of the first conductive layer and second portions 830 ₂ whichmay be referred to as recessed portions disposed in the first and secondtype openings 149 a-b of the first conductive layer as shown in FIG. 8b.

The process continues by forming a dielectric layer 840 over the secondconductive layer 830. In one embodiment, the dielectric layer includes asolder mask. Providing other types of dielectric material may also beuseful. The solder mask, in one embodiment, is formed by technique suchas dispensing, laminating or screen printing. Other suitable types oftechnique may be used. The solder mask covers sides/edges and firstsurface 830 a of the second conductive layer and fill the recesses 839of the second conductive layer. The solder mask, as formed, includes aplanar first surface 840 a as shown in FIG. 8 c.

The process continues to remove portions of the dielectric layer 840. Inone embodiment, portions of the dielectric layer may be removed byexposure and development techniques to create openings 849. Othersuitable techniques may also be employed to remove portions of thedielectric layer to form the openings 849.

Referring to FIG. 8e , the process continues to form bond pads 132 over,for example, portions of the second conductive layer. In one embodiment,bond pads are formed in the openings 849 of the dielectric layer. In oneembodiment, the bond pads are formed by a plating process. A conductivelayer, which may include the same material as the conductive carrier andtraces, such as copper, may be selectively plated over the exposedportions of the first surface 830 a of the conductive trace layer notcovered by the dielectric layer 340 to form the bond pads. As such, thedielectric layer also serves as a plating mask. The first surface of theconductive trace layer also serves as a base or substrate for theelectroplating process for forming the bond pads. The thickness of theplated bond pads, for example, is about 0.01-1.5 μm. Other suitablethicknesses and materials, for example, similar to that described inFIG. 7f , may also be useful.

A die 110 which includes circuit components similarly described in FIG.7h is attached by an adhesive layer 150 to the die region of the packagesubstrate as shown in FIG. 8f . For example, wire bonds 112 are formedto create electrical connection between the bond pads 132 which arecoupled to the conductive trace layer 830 on the package substrate anddie pads on the die. A cap 390 is formed to encapsulate the die and wirebonds and a second surface 390 b of the cap contacts the planar firstsurface 340 a of the dielectric layer. Features of the die, wire bonds,cap and the process involved are similar to that described in FIG. 7h .As such, these process steps will not be described or described indetail.

Referring to FIG. 8g , the second surface 707 b of the conductivecarrier is processed. In one embodiment, portions of the conductivecarrier are thinned or removed up to a desired thickness by suitabletechniques as described in FIG. 7i . As such, these process steps willnot be described or described in detail.

The process continues to form via contacts 107 and define conductivetraces 330 of the package substrate as shown in FIG. 8h . In oneembodiment, the via contacts of the package substrate are formed bypatterning the remaining conductive carrier using suitable techniques asdescribed in FIG. 7j . For example, patterning of the conductive carriercan be achieved by any suitable etching techniques. For example, apatterned etch mask (not shown), such as photoresist, is provided overthe second surface 717 of the thinned conductive carrier. An etch may beperformed using the etch mask to remove portions of the conductivecarrier unprotected by the etch mask to form via contacts 107 andopenings 779 separating the via contacts. The etch, for example, stopson the second surface 143 b of first conductive layer while forming thevia contacts. Thus, the first conductive layer also serves as an etchstop layer during formation of the via contacts so that the etch wouldnot over etch the conductive trace layer in non-via contact regions ofthe package substrate. The etch, for example, may be an isotropic etch,such as a wet etch. Other techniques for patterning the conductivecarrier may also be useful.

As described earlier, the conductive trace layer also lines theside/edges of the first conductive layer and bottom of the second typeopenings 149 b of the first conductive layer. Since the conductive tracelayer and the conductive carrier include the same material, the etchalso removes portions of the recessed portions of the conductive tracelayer which line the bottom of the second type openings 149 b of thefirst conductive layer, exposing protruded portions of the dielectriclayer in the second type openings as shown in FIG. 8h . Conductivetraces 330 of the package substrate as well as isolation of theconductive traces are thus defined. As such, via contacts and conductivetraces are simultaneously formed or defined by the same etch.

The thickness of the via contacts as formed, for example, issubstantially the same as the thickness of the thinned conductivecarrier. The via contacts, for example, may also include other suitablethicknesses. The via contacts 107 are directly coupled to the conductivetraces 330 in the via contact regions of the package substrate. Asshown, the first type openings 149 a in the first conductive layerallows the via contacts to be directly coupled to the recessed portionsof the conductive traces to form interconnect structures of the packagesubstrate.

After patterning the conductive carrier, the mask is removed. The mask,for example, may be removed by ashing. Other techniques for removing themask may also be useful.

Second type openings 149 b of the first conductive layer expose portionsof the sides of the first conductive layer and protruded portions of thesecond surface 340 b of the dielectric layer after the etch. Aninsulating layer 106, in one embodiment, is provided, filling the spaces779 between the via contacts and partially filling the second typeopenings 149 b between the first conductive layer as shown in FIG. 8i .As shown, the insulating layer includes protruded portions 106 p whichcontact portions of the second surface of the dielectric layer. Theinsulating layer isolates the via contacts. In one embodiment, theinsulating layer includes a dielectric material such as solder mask. Theinsulating layer, for example, may be formed by any suitable types ofdielectric materials and techniques. The insulating layer formed inbetween the via contacts may be referred to as the base substrate 106 ofthe package substrate.

The second surface 107 b of the via contacts, in one embodiment, may besubstantially coplanar or non-coplanar with the second surface of thebase substrate, similar to that described in FIG. 7 k.

The process continues by forming package contacts 160 coupled to the viacontacts, as shown in FIG. 8j . For example, the package contacts areformed on the second surface of the via contacts of the packagesubstrate, similar to that described in FIG. 7l . As such, commonfeatures will not be described or described in detail. A semiconductorpackage such as that shown in FIG. 3 is formed.

FIGS. 9a-f show another embodiment for forming a semiconductor package.The process is similar to that described in FIGS. 7a-l and FIGS. 8a-j .Referring to FIG. 9a , a dielectric layer 340, such as solder mask,includes a planar first surface 340 a and covers sides/edges and firstsurface 830 a of the second conductive layer and fills the recesses 839of the second conductive layer. Bond pads 132 are formed over portionsof the second conductive layer in the openings 849 of the dielectriclayer, the same as that described in FIG. 8e . As such, common elementsmay not be described or described in detail.

The process continues to remove portions of the dielectric layer asshown in FIG. 9b . In one embodiment, portions of the dielectric layer340 in the recesses 839 of the second conductive layer 830 are removed,exposing recessed portions of the conductive trace layer in the non-dieregion of the package substrate. Portions of the dielectric layer, forexample, may be removed by patterning the dielectric layer. For example,a patterned etch mask (not shown), such as photoresist, is provided overthe first surface of the dielectric layer. An etch may be performedusing the etch mask to remove portions of the dielectric layer. Theetch, for example, stops on the recessed portions 830 ₂ of secondconductive layer 830 while forming openings 949 in the dielectric layer440. Thus, the recessed portions 830 ₂ of the second conductive layeralso serves as an etch stop layer during removal of portions of thedielectric layer. The etch, for example, may be an isotropic etch, suchas a wet etch. Other techniques for patterning the dielectric layer mayalso be useful.

The process continues by attaching a die 110 similarly described in FIG.7h over an adhesive layer 150 prepared in the die region 105 a of thepackage substrate as shown in FIG. 9b . Wire bonds 112, for example, areformed to create electrical connection between the bond pads which arecoupled to the conductive trace layer and die pads on the die. A cap 490is formed to encapsulate the die and wire bonds. In one embodiment, thesecond surface of the cap 490 b contacts the planar first surface 440 aof the dielectric layer 440 while portions of the material of the capalso fills the openings 949 in the dielectric layer and recesses 839formed by the second conductive layer. Features of the die, wire bonds,cap and the process involved are similar to that described in FIG. 7h .As such, these process steps will not be described or described indetail.

Referring to FIG. 9c , the second surface 707 b of the conductivecarrier is processed, similar to that described in FIGS. 7i and 8g . Inone embodiment, portions of the conductive carrier in thinned or removedup to a desired thickness by suitable techniques as described in FIG. 7i. As such, these process steps will not be described or described indetail.

The process continues to form via contacts 107 and conductive traces 330of the package substrate as shown in FIG. 9d using suitable techniques,such as an etch process, as described in FIG. 7j and FIG. 8h . Forexample, the etch may be performed using the etch mask to removeportions of the conductive carrier unprotected by the etch mask to formvia contacts 107 and openings 779 separating the via contacts. The etch,for example, stops on the second surface 143 b of the first conductivelayer in non-via contact regions while forming via contacts 107 in thevia contact regions. Thus, the first conductive layer also serves as anetch stop layer during formation of the via contacts so that the etchwould not over etch the conductive trace layer in the non-via contactregions of the package substrate. Since the conductive trace layer andthe conductive carrier include the same material, the etch also removesportions of the recessed portions 830 ₂ of the conductive trace layerwhich line the bottom of the second type openings 149 b of the firstconductive layer, exposing protruded portions of the cap material in thesecond type openings as shown in FIG. 9d . Conductive traces 330 of thepackage substrate as well as isolation of the conductive traces are thusdefined. As such, via contacts and conductive traces are simultaneouslyformed or defined by the same etch.

The via contacts 107 are directly coupled to the conductive traces 330in the via contact regions of the package substrate. As shown, the firsttype openings 149 a in the first conductive layer allows the viacontacts to be directly coupled to the conductive traces to forminterconnect structures of the package substrate.

After patterning the conductive carrier, the mask is removed. The mask,for example, may be removed by ashing. Other techniques for removing themask may also be useful.

The second type openings 149 b in the first conductive layer exposeportions of the sides of the first conductive layer 143 and protrudedportions of the second surface 490 b of the cap after the etch. Aninsulating layer 106, in one embodiment, is provided, filling theopenings 779 between the via contacts 107 and partially filling thesecond type openings 149 b of the first conductive layer, formingprotruded portions 106 p as shown in FIG. 9e . As shown, the protrudedportions 106 p of the insulating layer also contact protruded portionsof the cap in the second type openings and portions of the secondsurface 440 b of the dielectric layer at peripheries 103 c-d of thepackage substrate. The insulating layer isolates the via contacts. Inone embodiment, the insulating layer includes a dielectric material suchas solder mask. Providing the insulating layer with the same material asthe cap may also be useful. The insulating layer, for example, may beformed by any suitable types of dielectric materials and techniques. Theinsulating layer formed in between the via contacts may be referred toas the base substrate 106 of the package substrate.

The process continues by forming package contacts 160 coupled to the viacontacts 107, as shown in FIG. 9f . For example, the package contactsare formed on the second surface 107 b of the via contacts, which may besubstantially coplanar or non-coplanar with the second surface 106 b ofthe base substrate, similar to that described in FIG. 7l . As such,common features will not be described or described in detail. Asemiconductor package such as that shown in FIG. 4 is formed.

FIGS. 10a-f show another embodiment for forming a semiconductor package.The process is similar to that described in FIGS. 7a-l , FIGS. 8a-j andFIGS. 9a-f . Referring to FIG. 10a , the process is at the stage similarto that described in FIG. 8e and FIG. 9a . As such, common elements maynot be described or described in detail.

Referring to FIG. 10b , the process continues to remove portions of thedielectric layer 340. In one embodiment, portions of the dielectriclayer are removed while portions of the dielectric layer 540 in the dieregion of the package substrate remains. Thus, portions of the secondconductive layer 830 in the non-die region of the package substrate andthe bond pads 132 are exposed. Portions of the dielectric layer, forexample, may be removed by suitable techniques as described in FIG. 9b .As such, these process steps and features may not be described ordescribed in detail.

The process continues by attaching a die 110 similarly described in FIG.7h over an adhesive layer 150 prepared in the die region 105 a of thepackage substrate as shown in FIG. 10b . Wire bonds 112, for example,are formed to create electrical connection between the bond pads 132which are coupled to the conductive trace layer 830 and die pads on thedie. A cap 590 is formed to encapsulate the die and wire bonds. In oneembodiment, the second surface 590 b of the cap contacts the firstsurface 830 a of the conductive trace layer while portions of thematerial of the cap also fills the recesses 839 formed by the secondconductive layer. Features of the die, wire bonds, cap and the processinvolved are similar to that described in FIG. 7h . As such, theseprocess steps will not be described or described in detail.

Referring to FIG. 10c , the second surface 707 b of the conductivecarrier 707 is processed, similar to that described in FIGS. 7i, 8g and9c . In one embodiment, portions of the conductive carrier in thinned orremoved up to a desired thickness by suitable techniques as described inFIG. 7i . As such, these process steps will not be described ordescribed in detail.

The process continues to form via contacts 107 and conductive traces 330of the package substrate as shown in FIG. 10d using suitable techniques,such as an etch process, as described in FIG. 7j , FIG. 8h and FIG. 9d .For example, the etch may be performed using the etch mask to removeportions of the conductive carrier unprotected by the etch mask to formvia contacts 107 and openings 779 separating the via contacts. The etch,for example, stops on the second surface 143 b of the first conductivelayer in non-via contact regions while forming via contacts 107 in thevia contact regions. The etch also removes portions of the recessedportions 830 ₂ of the conductive trace layer which line the bottom ofthe second type openings 149 b of the first conductive layer, exposingprotruded portions of the cap material in the second type openings 149 band at the peripheries 103 c-d of the package substrate and protrudedportions of the second surface of the dielectric layer 540 b in the dieregion 105 a as shown in FIG. 10d . Conductive traces 330 of the packagesubstrate as well as isolation of the conductive traces are thusdefined. As such, via contacts and conductive traces are simultaneouslyformed or defined by the same etch.

The via contacts 107 are directly coupled to the conductive traces 330in the via contact regions of the package substrate. As shown, the firsttype openings 149 a in the first conductive layer allows the viacontacts to be directly coupled to the conductive traces to forminterconnect structures of the package substrate.

After patterning the conductive carrier, the mask is removed. The mask,for example, may be removed by ashing. Other techniques for removing themask may also be useful.

Second type openings 149 b of the first conductive layer expose portionsof the sides of the first conductive layer 143 and protruded portions ofthe second surface 590 b of the cap after the etch. An insulating layer106, in one embodiment, is provided, filling the openings 779 betweenthe via contacts and partially filling the second type openings 149 b ofthe first conductive layer, forming protruded portions 106 p as shown inFIG. 10e . As shown, the protruded portions 106 p of the insulatinglayer also contact protruded portions of the second surface 590 b of thecap in the second type openings 149 b and at the peripheries 103 c-d ofthe package substrate as well as protruded portions of the secondsurface 540 b of the dielectric layer in the die region 105 a. Theinsulating layer isolates the via contacts. Materials and process offorming the insulating layer are similar to that described in FIG. 9e .As such, details of the materials and process will not be described ordescribed in detail.

The process continues by forming package contacts 160 coupled to the viacontacts 107, as shown in FIG. 10f . The package contacts, for example,are formed on the second surface 107 b of the via contacts, which may besubstantially coplanar or non-coplanar with the second surface 106 b ofthe base substrate, similar to that described in FIG. 7l . As such,common features will not be described or described in detail. Asemiconductor package such as that shown in FIG. 5 is formed.

FIGS. 11a-f show another embodiment for forming a semiconductor package.The process is similar to that described in FIGS. 7a-l , FIGS. 8a-j ,FIGS. 9a-f and FIGS. 10a-f . Referring to FIG. 11a , the process is atthe stage similar to that described in FIG. 8e , FIG. 9a and FIG. 10a .As such, common elements may not be described or described in detail.

Referring to FIG. 11b , the process continues to remove the dielectriclayer 340. In one embodiment, the entire dielectric layer 340 isremoved. Thus, the first surface 830 a of the second conductive layer830 and the bond pads 132 are exposed. The dielectric layer 340, forexample, may be removed by suitable techniques, such as an etch process,as described in FIG. 9b . As such, these process steps and features maynot be described or described in detail. The etch, for example, stops onthe first surface 830 a of the second conductive layer and the bondpads.

The process continues by attaching a die 110 similarly described in FIG.7h over an adhesive layer 150 prepared in the die region 105 a of thepackage substrate as shown in FIG. 11b . Wire bonds 112, for example,are formed to create electrical connection between the bond pads whichare coupled to the conductive trace layer 830 and die pads on the die. Acap 690 is formed to encapsulate the die and wire bonds. In oneembodiment, the second surface 690 b of the cap contacts the firstsurface 830 a of the conductive trace layer while portions of thematerial of the cap also fill the recesses 839 formed by the secondconductive layer 830. Features of the die, wire bonds, cap and theprocess involved are similar to that described in FIG. 7h . As such,these process steps will not be described or described in detail.

Referring to FIG. 11c , the second surface 707 b of the conductivecarrier is processed, similar to that described in FIGS. 7i, 8g, 9c and10c . In one embodiment, portions of the conductive carrier in thinnedor removed up to a desired thickness by suitable techniques as describedin FIG. 7i . As such, these process steps will not be described ordescribed in detail.

The process continues to form via contacts 107 and conductive traces 330of the package substrate as shown in FIG. 11d using suitable techniques,such as an etch process, as described in FIG. 7j , FIG. 8h , FIG. 9d andFIG. 10d . For example, the etch may be performed using the etch mask toremove portions of the conductive carrier unprotected by the etch maskto form via contacts 107 and openings 779 separating the via contacts.The etch, for example, stops on the second surface 143 b of the firstconductive layer in non-via contact regions while forming via contacts107 in the via contact regions. The etch also removes portions of therecessed portions 830 ₂ of the conductive trace layer which line thebottom of the second type openings 149 b of the first conductive layer,exposing protruded portions of the cap material in the second typeopenings 149 b in the non-die region 105 b and at the peripheries 103c-d of the package substrate as well as portions of the adhesive layer150 in the die region as shown in FIG. 11d . Conductive traces 330 ofthe package substrate as well as isolation of the conductive traces arethus defined. As such, via contacts and conductive traces aresimultaneously formed or defined by the same etch.

The via contacts 107 are directly coupled to the conductive traces 330in the via contact regions of the package substrate. As shown, the firsttype openings 149 a in the first conductive layer allows the viacontacts to be directly coupled to the conductive traces to forminterconnect structures of the package substrate.

After patterning the conductive carrier, the mask is removed. The mask,for example, may be removed by ashing. Other techniques for removing themask may also be useful.

Second type openings 149 b of the first conductive layer expose portionsof the sides of the first conductive layer, protruded portions of thesecond surface 690 b of the cap and portions of the second surface 330 bof the conductive traces after the etch. An insulating layer 106, in oneembodiment, is provided, filling the spaces 779 between the via contactsand partially filling the second type openings 149 b of the firstconductive layer, forming protruded portions 106 p as shown in FIG. 11e. As shown, the protruded portions of the insulating layer also contactprotruded portions of the second surface 690 b of the cap in the secondtype openings 149 b in the non-die region 105 b and at the peripheries103 c-d of the package substrate and portions of the adhesive layer 150in the die region 105 a. The insulating layer isolates the via contacts.Materials and process of forming the insulating layer are similar tothat described in FIG. 9e . As such, details of the materials andprocess will not be described or described in detail.

The process continues by forming package contacts 160 coupled to the viacontacts 107, as shown in FIG. 11f . The package contacts, for example,are formed on the second surface of the via contacts, which may besubstantially coplanar or non-coplanar with the second surface 107 b ofthe base substrate, similar to that described in FIG. 7l . As such,common features will not be described or described in detail. Asemiconductor package such as that shown in FIG. 6 is formed.

The embodiments described with respect to FIGS. 8a-j , FIGS. 9a-f ,FIGS. 10a-f and FIGS. 11a-f include some or all advantages as describedwith respect to FIG. 7a-l . As such, these advantages will not bedescribed or described in detail. The embodiments, as described withrespect to FIGS. 8a-j , FIGS. 9a-f , FIGS. 10a-f and FIGS. 11a-f resultin additional advantages. For example, as described in the embodimentsof FIGS. 8a-j , FIGS. 9a-f , FIGS. 10a-f and FIGS. 11a-f , portions ofthe first surface 106 a of the base substrate includes protrudedportions 106 p which partially occupy the second type openings 149 b ofthe first conductive layer. As such, the second type openings 149 b ofthe first conductive layer in the non-via contact regions of the packagesubstrate provide more surface area for the base substrate toeffectively hold the via contacts. As such, the reliability of thesemiconductor package is further enhanced.

FIGS. 12a-e show another embodiment for forming a semiconductor package.The process is similar to that described in FIGS. 7a-l , FIGS. 8a-j ,FIGS. 9a-f , FIGS. 10a-f and FIGS. 11a-f . As such, common elements maynot be described or described in detail.

Referring to FIG. 12a , a base carrier or a leadframe 1200 is provided.The base carrier, in one embodiment, includes a conductive carrierhaving first and second major surfaces 1200 a-b. The first and secondmajor surfaces, for example, include planar surfaces. Providing any oneof the major surfaces to be non-planar may also be useful. Theconductive carrier, for example, includes Cu, Cu alloy, Fe or Ni—Fealloy, similar to that described in FIG. 7a . Other suitable types ofconductive materials may also be useful. In one embodiment, thethickness of the conductive carrier 1200 is substantially the same asthe thickness of via contacts 107 of the package substrate to be formed.For example, the thickness of the conductive carrier is about 100-300μm. Other suitable thicknesses may also be useful, depending on thedesired thickness of the via contacts. The conductive carrier, forexample, may serve as part of the interconnect structures, such as viacontacts, of the package substrate as will be described later.

In one embodiment, the process continues by providing a support carrier1300. The support carrier, for example, is a temporary carrier forprocessing the die package. The carrier should be sufficiently rigid toserve as a support and withstand further processing steps. By way ofnon-limiting example, the support carrier may be a silicon, standardsteel, Cu or Cu alloy. Various types of materials may be used to formthe support carrier.

In one embodiment, an adhesive 1500 is provided on a first surface 1300a of the support carrier to facilitate temporary bonding of theconductive carrier 1200 onto the support carrier 1300. Other temporarybonding techniques may also be useful. The adhesive, for example, can beany type of adhesive that provides temporary bonding of the conductivecarrier. The adhesive may be in different forms. For example, theadhesive may be a tape, liquid or paste. The adhesive may be provided onthe support carrier using various techniques. The technique employed maydepend on the type or form of the adhesive. For example, a tape adhesivemay be provided on the support carrier by lamination, a paste adhesivemay be provided on the support carrier by printing while a liquidadhesive may be provided on the substrate by spin coating.

In one embodiment, the second surface 1200 b of the conductive carrieris attached to the support carrier 1300 via the adhesive 1500 as shownin FIG. 12b . The conductive carrier is attached to the support carrierusing any suitable techniques according to the equipment and type ofadhesive used.

The process continues to form the first and second conductive layerswith predefined openings and bond pads. In one embodiment, the processcontinues, as similarly described in FIGS. 7b-g , except that theconductive carrier having a thickness substantially the same as thethickness of a desired via contacts which is attached to the supportcarrier. As such, these process steps will not be described or describedin detail. The process continues until a partially processed packagesubstrate attached to the support carrier as shown in FIG. 12c isformed.

The process continues by attaching a die 110, electrically coupling thedie to the conductive traces 130 by wire bonds and forming a cap 190 toencapsulate the die and wire bonds 112 as shown in FIG. 12d . Featuresof the die, wire bonds, cap and the process involved are similar to thatdescribed in FIG. 7h and thus the details will not be described ordescribed in detail.

Referring to FIG. 12e , the support carrier 1300 and the adhesive 1500are separated from the conductive carrier 1200 after forming the cap. Inone embodiment, a debonding treatment is performed. The debondingtreatment may, for example, cause the adhesive to lose or reduce itsadhesive strength to allow separation of the die assembly from thesupport carrier. The debonding treatment, in one embodiment, includes atemperature or heat treatment. When heated to the debonding temperature,the adhesive loses or reduces its adhesive strength. Other types ofdebonding treatments may also be useful. The debonding treatment maydepend on the type of adhesive used. The debonding treatment may includechemical treatment, such as applying a solvent to dissolve the adhesive,or a mechanical treatment, such as pulling or twisting, to separate thedie assembly from the support carrier.

The partially processed package after the removal of the support carrieras shown in FIG. 12e is similar to the partially processed package asshown in FIG. 7i . In one embodiment, the thickness of the conductivecarrier as shown in FIG. 12e has been pre-prepared according to thedesired via contact thickness. As such, additional process to removeexcess material of the conductive carrier is avoided.

The process continues to form via contacts, base substrate and packagecontacts, as similarly described in FIG. 7j and onwards. As such, theseprocess steps will not be described or described in detail. The processcontinues until a package similar to that shown in FIG. 1 is formed.

The process as described in FIGS. 12a-e may be modified to producepackages as shown in FIGS. 3-6. For example, after the conductivecarrier 1200 is attached to the support carrier 1300, the process offorming the first and second conductive layers, dielectric layer andbond pads as described in FIGS. 7b-g may be replaced by the processdescribed in FIGS. 8a-e and further processing to form a partiallyprocessed package substrate as shown in FIG. 8f , FIG. 9b , FIG. 10b andFIG. 11b , omitting the step of removing excess material of theconductive carrier since the conductive carrier having a thicknesssubstantially the same as the thickness of a desired via contacts hasalready been pre-prepared. As such, these process steps will not bedescribed or described in detail. The process then continues from toremove the support carrier as described in FIG. 12d and onwards to untila complete semiconductor package such as that shown in FIG. 3, 4, 5 or 6is formed.

FIGS. 13a-d show another embodiment for forming a semiconductor package.The process is similar to that described in FIGS. 7a-l , FIGS. 8a-j ,FIGS. 9a-f , FIGS. 10a-f , FIGS. 11a-f and FIGS. 12a-e . As such, commonelements may not be described or described in detail.

Referring to FIG. 13a , a partially processed package substrate isprovided. The partially process package substrate is at the stage ofprocessing as described in FIG. 7g . For example, first and secondconductive layers with predefined openings and bond pads are formed overthe conductive carrier 707. The partially processed package substratemay optionally include a dielectric layer 140, such as solder mask, inthe die region 105 a of the package substrate. As such, common featuresmay not be described or described in detail.

In one embodiment, the process continues by processing the secondsurface 707 b of the conductive carrier. In one embodiment, portions ofthe conductive carrier 707 are removed. For example, the second surface707 b of the conductive carrier is patterned to remove excess material.For example, the conductive carrier is thinned or removed up to asuitable thickness. The conductive carrier may be thinned to a desiredvia contact thickness as shown in FIG. 13b . [The second major surfaceof the conductive carrier may be removed using etch, grinding orpolishing technique. The etch, for example, includes wet etch/chemicaletch. Other techniques for thinning the conductive carrier may also beuseful.

In one embodiment, the process continues by providing a support carrier1300 as shown in FIG. 13c . The support carrier, for example, is atemporary carrier for processing the die package and an adhesive 1500 isprovided on a first surface 1300 a of the support carrier to facilitatetemporary bonding of the partially processed package substrate onto thesupport carrier. The features of the support carrier and adhesive arethe same as that described in FIG. 12a . As such, these features willnot be described or described in detail.

Referring to FIG. 13d , the process continues by attaching the partiallyprocessed package substrate to the support carrier 1300. For example,the second surface of the conductive carrier 717 is attached to thesupport carrier via the adhesive as shown in FIG. 13d . The resultantstructure, as shown in FIG. 13d , is the same as that shown in FIG. 12c. As such, common features may not be described.

The process continues to complete the semiconductor package, assimilarly described in FIGS. 12d-e and FIG. 7j and onwards. As such,these process steps will not be described or described in detail. Theprocess continues until a package similar to that shown in FIG. 1 isformed.

The process as described in FIGS. 13a-d may be modified to producepackages as shown in FIGS. 3-6. For example, the partially processpackage as shown as described in FIG. 13a may be replaced by a partiallyprocessed package at the stage of processing described in FIG. 8e, 9a,10a or 11 a. The process then continues to further process the secondsurface of the conductive carrier as described in FIG. 13b . As such,these process steps will not be described or described in detail. Theprocess then continues from FIG. 13b and onwards to until a completesemiconductor package such as that shown in FIG. 3, 4, 5 or 6 is formed.

The embodiments described with respect to FIGS. 12a-e and FIGS. 13a-dinclude some or all advantages as described with respect to FIG. 7a-l ,FIGS. 8a-j , FIGS. 9a-f , FIGS. 10a-f and FIGS. 11a-f . As such, theseadvantages will not be described or described in detail. Theembodiments, as described with respect to FIGS. 12a-e and FIGS. 13a-dresult in further advantages. For example, in the embodiment describedwith respect to FIGS. 12a-e , a conductive carrier having a pre-definedthickness which is substantially the same as the thickness of the viacontacts is pre-prepared. This eliminates the step of removing excessmaterial of the conductive carrier to the thickness of the via contactsby an etch process which may result in overetching the conductivecarrier and further reduces costs. Moreover, the use of a temporarycarrier and adhesive as described in these embodiments providesufficient support to the conductive carrier during assembly of the diepackage. The temporary carrier may be recycled after use and thereforeprovides a relatively cost savings method for producing thesemiconductor package.

The processes, as described in FIGS. 7a-l , FIGS. 8a-j , FIGS. 9a-f ,FIGS. 10a-f , FIGS. 11a-f , FIGS. 12a-e and FIGS. 13a-d include a wirebonded die. In another embodiment, the process may include a flip chiptype of die. It is understood that modifications may be made to formcontact pads which matches the die contacts of the flip chip die forflip chip applications. It is also understood that for flip chipapplication, first surface of the cap may be covering the inactivesurface of the flip chip or substantially coplanar with the inactivesurface of the flip chip. As such, details for flip chip application maynot be described or described in detail.

The invention may be embodied in other specific forms without departingfrom the spirit or essential characteristics thereof. The foregoingembodiments, therefore, are to be considered in all respectsillustrative rather than limiting the invention described herein.

What is claimed is:
 1. A package substrate comprising: a base substratehaving first and second major surfaces and a plurality of via contactsextending through the first to the second major surfaces of the basesubstrate; a first conductive layer disposed over and in direct contactwith the first surface of the base substrate and via contacts, whereinthe first conductive layer comprises a plurality of openings which areconfigured to match conductive trace layout of the package substrate;and conductive traces disposed over the first conductive layer, whereinthe conductive traces are directly coupled to the via contacts throughsome of the openings of the first conductive layer.
 2. The packagesubstrate of claim 1 wherein: the via contacts and the conductive tracescomprise a first conductive material; and the first conductive layercomprises a second conductive material which is different than the firstconductive material, wherein the second conductive material comprises amaterial which provides etch selectivity between the first conductivelayer and the via contacts.
 3. The package substrate of claim 2 wherein:the first conductive material comprises copper and the second conductivematerial comprises nickel; and bottom surface of the conductive tracesare only in direct contact with the first conductive layer, or bottomsurface of the conductive traces are only in direct contact with thefirst conductive layer and via contacts.
 4. A package substratecomprising: a base substrate having first and second major surfaces anda plurality of via contacts extending through the first to the secondmajor surfaces of the base substrate; a first conductive layer having aplurality of openings disposes over the first surface of the basesubstrate and via contacts, wherein the openings are configured to matchconductive trace layout of the package substrate and wherein the firstmajor surface of the base substrate includes protruded portions whichpartially occupy some of the openings of the first conductive layer; andconductive traces disposes over the first conductive layer, wherein theconductive traces are directly coupled to the via contacts through someof the openings of the first conductive layer.
 5. A semiconductorpackage comprising: a package substrate having first and second majorsurfaces, wherein the package substrate comprises a base substrate and aplurality of via contacts extending through the first to the secondmajor surface of the package substrate; a first conductive layerdisposed over and in direct contact with the base substrate and viacontacts of the package substrate, wherein the first conductive layercomprises first and second type openings which are configured to matchconductive trace layout of the package substrate; conductive tracesdisposed over the first conductive layer, wherein the conductive tracesare directly coupled to the via contacts through the first type openingsof the first conductive layer; a die having conductive contacts on itsfirst or second surfaces disposed over a die region of the packagesubstrate, wherein the conductive contacts of the die are electricallycoupled to the conductive traces; and a cap disposed over the packagesubstrate to encapsulate the die.
 6. The semiconductor package of claim5 wherein: the via contacts and the conductive traces comprise a firstconductive material; and the first conductive layer comprises a secondconductive material which is different than the first conductivematerial.
 7. The semiconductor package of claim 6 wherein the firstconductive material comprises copper and the second conductive materialcomprises nickel.
 8. The semiconductor package of claim 5 wherein thebase substrate comprises first and second surfaces, wherein the firstsurface of the base substrate comprises protrusions which partiallyoccupy the second type openings of the first conductive layer.
 9. Thesemiconductor package of claim 8 comprising a dielectric layer disposedover the conductive traces, wherein the dielectric layer isolates theconductive traces.
 10. The semiconductor package of claim 9 wherein: thedielectric layer comprises openings in a non-die region of the packagesubstrate; and the cap includes first and second major surfaces, whereinthe second major surface of the cap comprises protrusions which occupythe openings of the dielectric layer.
 11. The semiconductor package ofclaim 9 wherein the dielectric layer is disposed over the conductivetraces in the die region of the package substrate.
 12. The semiconductorpackage of claim 11 wherein: the cap comprises first and second majorsurfaces; and the second major surface of the cap comprises protrudedportions which occupy openings separating the conductive traces.
 13. Thesemiconductor package of claim 8 wherein: the conductive traces comprisefirst portion and second portion; and the first portion of theconductive traces is disposed over first surface of the first conductivelayer while the second portion of the conductive traces lines sides andbottom of the first type opening of the first conductive layer whichcorresponds to a recessed portion of the conductive traces.
 14. Thesemiconductor package of claim 13 wherein the conductive traces aredirectly coupled to the via contacts through the recessed portion of theconductive traces.
 15. The semiconductor package of claim 14 comprisinga dielectric layer disposed over the conductive traces in the die andnon-die regions of the package substrate.
 16. The semiconductor packageof claim 15 wherein: the dielectric layer comprises first and secondtype openings; and the first type openings of the dielectric layerexpose the recessed portion of the conductive traces while the secondtype openings of the dielectric layer expose surfaces of the protrusionsof the base substrate.
 17. The semiconductor package of claim 5comprising an insulating layer which covers and fills spaces between theconductive traces in the die region of package substrate.
 18. Thesemiconductor package of claim 5 wherein: the cap comprises first andsecond major surfaces; and portions of the second major surface of thecap comprise protruded portions which occupy the second type openings ofthe first conductive layer and spaces between the conductive traces. 19.The semiconductor package of claim 5 wherein the via contacts aredisposed only in non-die regions of the package substrate.
 20. Thesemiconductor package of claim 5 wherein the die comprises wire bondedtype of die, flip chip or TSV type of die.